LG Inverter Heat Pump 80 Gal vs Rinnai REHP80

Last updated: October 22, 2026

The LG Inverter Heat Pump 80 Gal is the better heat pump water heater overall, rated 3.8 to 3.7. The LG Inverter Heat Pump 80 Gal leads on cold rooms, noise and hot water. The Rinnai REHP80 wins on warranty.

LG Inverter Heat Pump 80 Gal vs Rinnai REHP80

Prices were last checked October 22, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.

Which should you buy?

Scores side by side

Each factor is scored 0-100 against the same fixed reference points for every 80 gallon heat pump water heater; a clear win is highlighted. How we rank explains each one.

Factor weightLG Inverter Heat Pump 80 GalRinnai REHP80
Overall rating3.8/53.7/5
Efficiency 35%64 3.90 UEF71 4.00 UEF
Hot water 20%76 94 gallons in the first hour64 91 gallons in the first hour
Warranty 20%30 10-year tank, 1-year parts75 10-year tank, 10-year parts, 1-year labor
Cold rooms 15%88 heat pump runs down to 23 °F room air30 heat pump runs down to 37.4 °F room air
Noise 10%88 42 dB(A)44 49 dB(A)

Specifications

LG Inverter Heat Pump 80 GalRinnai REHP80
Ratings (ENERGY STAR)
Size (nominal)80 gal80 gal
Tank volume (measured)72 gal75 gal
Uniform Energy Factor3.904.00
First-hour rating94 gal91 gal
Draw patternHighHigh
Yearly energy use1,272 kWh1,225 kWh
Heat pump cut-off (low)23 °F37.4 °F
Sound level42 dB(A)49 dB(A)
ENERGY STAR ID26822633531242
Installation
Power240 V240 V
Circuit30 A, 208/240 V30 A, 208/240 V
Backup element5,000 W4,500 W
Operating air range23 to 120 °F37 to 107 °F
Minimum room size700 cu ft700 cu ft
Size62.7 in tall, 19.7 in across74.2 in tall, 25.7 in across
Weight224 lb290 lb
RefrigerantR-134aR-134a
Features
Wi-FiBuilt inNo
AppLG ThinQ-
Leak detection-No
ModesAuto, Turbo, Heat Pump, VacationEconomy, Heat Pump, Hybrid, E-Heater, Vacation
Warranty and models
Warranty10 yr tank, 1 yr parts10 yr tank, 10 yr parts, 1 yr labor
Released2023-042024-08

All heat pump water heater comparisons →